From the Allgaeu area.
From grandmother's more thrifty times; rarely encountered today.
Melt the butter and stir in the flour. Add meat broth. Bring to a boil, then add the sliced cheese and stir until cheese has dissolved. Remove soup from heat, and whisk in the egg yolk mixture. Add salt, pepper, and sugar to taste.
Dice the bread and in the butter, saute until golden brown.
Add to soup just before serving.
From: D'SCHWAEBISCH' KUCHE' by Aegidius Kolb and Leonhard Lidel, Allgaeuer Zeitungsverlag, Kempten. 1976. (Translation/Conversion: Karin Brewer) Posted by: Karin Brewer, Cooking Echo, 9/92